考虑桥面风场等效气动效应的行车安全性分析

SAFETY ANALYSIS OF ROAD VEHICLES CONSIDERING THE EQUIVALENT AERODYNAMIC EFFECTS OF WIND FIELD ABOVE BRIDGE DECK

侧风作用下桥上通行车辆容易遭受行车安全问题。通过节段模型风洞试验,测试了主梁行车道位置上方一定高度范围内风场分布特性。基于车辆气动力和力矩等效的方法,采用等效风速和比例系数来考虑桥面气动绕流对车辆气动力特性的影响。在风-汽车-桥耦合振动研究的基础上,采用无量纲的侧倾和侧滑安全因子评价车辆的行车安全性,分析了风速和车速对不同类型车辆行车安全性的影响。结果表明:车辆的行车安全性随着风速和车速的增大而逐渐降低;桥面风场等效气动效应会降低集装箱车和旅行巴士的行车安全性,集装箱车RSF和SSF最大相对误差分别高达28.0%和184.3%。

Vehicles running on bridges under crosswind are susceptible to safety issues. The wind field characteristics above traffic lanes within a certain height are available by means of the section model wind tunnel tests. Based on the equivalent method of the aerodynamic forces and moments for road vehicles, both the equivalent wind velocity and scale factor are adopted to investigate the effects of the flow around bridge deck on the aerodynamic forces of road vehicles. The dimensionless rolling and sideslip safety factors are introduced to evaluate the vehicle safety on the basis of the coupling vibration of wind-vehicle-bridge system. It investigates the effects of wind velocity and vehicle speed on the safety of different types of vehicles. Results indicate that the level of safety of vehicles decreases with the increase of wind velocity and vehicle speed; the safety of articulated lorry and coaches are reduced considering the equivalent aerodynamic effects of wind field above bridge decks. The maximum relative error of the RSF and SSF for articulated lorry reaches up to 28.0% and 184.3%, respectively.